The inventive concept relates to a semiconductor memory device, and more particularly, to a sense amplifier for improving an effective sensing margin based on an operation of cancelling an offset of the sense amplifier.
A dynamic random-access memory (DRAM) among memory devices operates in a manner in which data is written by electric charges stored in cell capacitors of memory cells. Memory cells are connected to a bit line (BL) and a complementary bit line (BLB). In a DRAM, when a read operation or a refresh operation is performed, a sense amplifier senses and amplifies a voltage difference between the bit line and the complementary bit line. Semiconductor devices constituting the sense amplifier may have different device characteristics, for example, different threshold voltages, due to a process variation, temperature, or the like. Such different device characteristics may cause offset noise in the sense amplifier. Due to the offset noise, an effective sensing margin of the sense amplifier may be reduced, and performance of the DRAM may be reduced.